1

Of Cassavas, Corn, andChilies

Food preparation and nutritionFood preparation and nutrition

Methods of Food Preparation:Adapting foods to people

How a food is prepared for consumptionHow a food is prepared for consumptionaffects the presence, and availability ofaffects the presence, and availability ofsome compounds and elementssome compounds and elements

Ex: Vitamin C is heat sensitiveEx: Vitamin C is heat sensitive

With cooking, the amount of vitaminWith cooking, the amount of vitaminC declinesC declines

Processing can be particularly importantProcessing can be particularly importantwhen the foods are staple foodswhen the foods are staple foods

Example of soybeans

Soybeans are an Asian legume rich in theSoybeans are an Asian legume rich in theamino acids that complement amino acidsamino acids that complement amino acidsfound in cerealsfound in cereals

Soybeans can cause serious indigestionSoybeans can cause serious indigestionbecause they contain antitrypsin factor (ATF),because they contain antitrypsin factor (ATF),which binds the enzyme tripsin that thewhich binds the enzyme tripsin that thedigestive system uses to break down thedigestive system uses to break down theprotein in soybeansprotein in soybeans

If soybeans are boiled for hours or roastedIf soybeans are boiled for hours or roastedat high temperatures, the ATF isat high temperatures, the ATF isdeactivated, but the amino acids aredeactivated, but the amino acids aredestroyeddestroyed

Soybean use

Chinese and Japanese cooking usesChinese and Japanese cooking usesfermentation to make soy sauce, infermentation to make soy sauce, inwhich the action of the microorganismswhich the action of the microorganismsdeactivate ATF, yet amino acids remaindeactivate ATF, yet amino acids remain

ATF is also removed in process ofATF is also removed in process ofmaking tofu by using certain salts tomaking tofu by using certain salts toprecipitate digestible proteins out ofprecipitate digestible proteins out ofthe soybeans.the soybeans.

Tukanoans and Cassava

Some Amazonian Indians have developed aSome Amazonian Indians have developed amethod to eliminate a toxic compound,method to eliminate a toxic compound,cyanide, in cassavacyanide, in cassava

Cassava is highly toxic in the raw state.Cassava is highly toxic in the raw state.

Cassava is a dietary staple of many people inCassava is a dietary staple of many people inthe worldthe world

Humans can tolerate small amounts (e.g.,Humans can tolerate small amounts (e.g.,that found in cigarette smoke), but largethat found in cigarette smoke), but largeamounts are toxicamounts are toxic

Tukanoans

The amount of cyanide consumed byThe amount of cyanide consumed bythe Tukanoan Indians of Colombia isthe Tukanoan Indians of Colombia islarge enough to cause deathlarge enough to cause death

Cassava is consumed in the form of aCassava is consumed in the form of athick soft bread made daily from whitethick soft bread made daily from white--fleshed rootsfleshed roots

It is served with fish, game, and insectsIt is served with fish, game, and insects

2

CASSAVA Cassava

Cassava is also known asCassava is also known as YuccuYuccu and manioc.and manioc.

It was first produced in Paraguay and Brazil,It was first produced in Paraguay and Brazil,but is now used as a staple food all over thebut is now used as a staple food all over theworldworld

All parts of the cassava plant contain theAll parts of the cassava plant contain thecyanide compound and it is mostcyanide compound and it is mostconcentrated in the leavesconcentrated in the leaves

There are different varieties of cassava andThere are different varieties of cassava andthe more bitter ones have more of thethe more bitter ones have more of thecyanide compoundcyanide compound

The cyanide is in the plant to protect it fromThe cyanide is in the plant to protect it frompredatorspredators

Cassava plants Cassava Preparation

Roots are rasped to remove outer peelRoots are rasped to remove outer peel

Roots are washed and grated to a wateryRoots are washed and grated to a waterymashmash

The mash shows a dramatic increase in freeThe mash shows a dramatic increase in freecyanide, which can then be washed awaycyanide, which can then be washed away(being water soluble)(being water soluble)

The mash is separated into 3 parts: liquids,The mash is separated into 3 parts: liquids,starch, and fiberstarch, and fiber

The separation is done by washing withThe separation is done by washing withwater and juices and squeezing mashwater and juices and squeezing mashthrough a basketthrough a basket

Washing the peeled roots Cassava Preparation

Once the starch has settled the supernatantOnce the starch has settled the supernatantis decanted to make a drink calledis decanted to make a drink called manicueramanicuera

The starch and fiber are stored overnight forThe starch and fiber are stored overnight for24 to 48 hours24 to 48 hours

They are then recombined and baked intoThey are then recombined and baked intobreadbread

To recombine the fiber is dewatered in aTo recombine the fiber is dewatered in abasket and toasted and then combinedbasket and toasted and then combinedwith the starchwith the starch

The amount of total cyanide appears toThe amount of total cyanide appears todecrease with storage and cookingdecrease with storage and cooking

3

Flour production Bread baking

Does processing decrease the nutritionalvalue of the cassava?

For the Tukanoans, the answer is noFor the Tukanoans, the answer is no

Many nutrients are lost by losing the skin,Many nutrients are lost by losing the skin,but other processing techniques that usebut other processing techniques that usemore heat tend to have greater nutrientmore heat tend to have greater nutrientlosseslosses

Also drinking theAlso drinking the manicueramanicuera helps tohelps torecover many of those lost nutrientsrecover many of those lost nutrients

Dufour suggests that these processingDufour suggests that these processingtechniques could be used elsewhere in thetechniques could be used elsewhere in theworld to make this staple food more nutritiousworld to make this staple food more nutritious

Maize Processing

Maize Processing

The rise of maize (The rise of maize (Zea maysZea mays) as a) as amajor cultivar in the New World frommajor cultivar in the New World from7,000 b.p. in Mexico was not without a7,000 b.p. in Mexico was not without abiological pricebiological price

Corn is of limited nutritional benefitCorn is of limited nutritional benefitwithout appropriate processing orwithout appropriate processing ortreatment to enhance availability oftreatment to enhance availability ofnutrientsnutrients

Maize Processing, 2

90+% of the protein in the corn kernel comes90+% of the protein in the corn kernel comesin four formsin four forms

Albumins, available, low qualityAlbumins, available, low quality

Globulins, available, low qualityGlobulins, available, low quality

Zein, relatively available, low lysine, lowZein, relatively available, low lysine, lowtryptophan, high leucine to isoleucine ratiotryptophan, high leucine to isoleucine ratio

Glutelin, soluble in alkaline solution, highGlutelin, soluble in alkaline solution, highlysine, moderate tryptophan, low leucine tolysine, moderate tryptophan, low leucine toisoluecine ratioisoluecine ratio

4

Maize Processing, 3

Nutritional deficiencies of corn when not appropriatelyNutritional deficiencies of corn when not appropriatelyprocessed:processed:

Low in essential amino acids lysine andLow in essential amino acids lysine andtryptophantryptophan

High leucine to isoleucine ratioHigh leucine to isoleucine ratio

Low availability of niacinLow availability of niacin

Thought to be bound by an insoluble substanceThought to be bound by an insoluble substance

Can be synthesized from excess tryptophanCan be synthesized from excess tryptophan

Synthesis of niacin is inhibited by leucineSynthesis of niacin is inhibited by leucine

Leucine inhibition is removed by isoleucineLeucine inhibition is removed by isoleucine

Maize Processing, 4

Most severe nutritional problem with a high maize diet isMost severe nutritional problem with a high maize diet isthe potential for pellagra from niacin deficiencythe potential for pellagra from niacin deficiency

Symptoms:Symptoms:

Dermatitis: Skin inflamation where exposed toDermatitis: Skin inflamation where exposed tosunlightsunlight

Diarrhea: Loss of acidity may allow bacterial growth,Diarrhea: Loss of acidity may allow bacterial growth,causing a decreased ability of the intestinal mucosacausing a decreased ability of the intestinal mucosato facilitate absorptionto facilitate absorption

Depression: Irritability, headaches, sleeplessness,Depression: Irritability, headaches, sleeplessness,loss of memory hallucinations, delusions ofloss of memory hallucinations, delusions ofpersecution, and severe depressionpersecution, and severe depression

Death through organ failureDeath through organ failure

Maize Processing, 5 Historically pellagra has been the onlyHistorically pellagra has been the only

endemic nutritional disease native to the U.S.endemic nutritional disease native to the U.S.

In 1918, there were an estimated 10,000In 1918, there were an estimated 10,000pellagra deaths and 100,000 cases,pellagra deaths and 100,000 cases,primarily in the cotton growing regions ofprimarily in the cotton growing regions ofthe Southern U.S.the Southern U.S.

pellagra became a public health issue inpellagra became a public health issue inthe South during the depressionthe South during the depression

•• Families growing corn and eatingFamilies growing corn and eatingmostly nonmostly non--alkaline processed gritsalkaline processed grits

Maize Processing, 6

Alkali processing changes the nutritionalAlkali processing changes the nutritionalquality of maizequality of maize

Tortilla manufacture in MesoAmericaTortilla manufacture in MesoAmerica

Heat dried corn to boiling in 5% limeHeat dried corn to boiling in 5% lime--water solutionwater solution

Cool, discard liquid, wash corn, grindCool, discard liquid, wash corn, grindinto a doughinto a dough

Form pancake shape and cook on hotForm pancake shape and cook on hotclay griddleclay griddle

Maize Processing, 7

Sources of alkali (turning the water to aSources of alkali (turning the water to abase pH, higher than 7.0) include thebase pH, higher than 7.0) include themineral lime from bedrock in manymineral lime from bedrock in manyareas, commercial lye and sodaareas, commercial lye and sodapreparations, and wood ashpreparations, and wood ash

Lime has the added benefit ofLime has the added benefit ofincreasing dietary calciumincreasing dietary calcium

Maize Processing, 8 Alkali processing increases theAlkali processing increases the

bioavailability of niacin and glutelin,bioavailability of niacin and glutelin,while decreasing availability of Zeinwhile decreasing availability of Zein

The net effect is to decrease theThe net effect is to decrease thelikelihood of pellagra on a high corn dietlikelihood of pellagra on a high corn diet

The populations most likely toThe populations most likely toexperience pellagra historically areexperience pellagra historically arethose that relied heavily on itthose that relied heavily on it

Native AmericansNative Americans

5

Maize Processing, 9

Many New World Societies were very heavilyMany New World Societies were very heavilyreliant on maize cultivation and alkalireliant on maize cultivation and alkaliprocessingprocessing

Katz and colleagues used the HRAF filesKatz and colleagues used the HRAF filesto assess processing technique (alkali orto assess processing technique (alkali ornot), and cultivation and consumption ofnot), and cultivation and consumption ofcorn on 4 point scale (none to high)corn on 4 point scale (none to high)

They found a good association betweenThey found a good association betweenlevel of cultivation, consumption, and alkalilevel of cultivation, consumption, and alkaliprocessingprocessing

Maize Processing, 10

MaizeCultivation

MaizeProcessing

Maize Consumption

None Low Moderate HighHigh Alkalai 0 0 10b 7

Not Alkalai 0 0 0 0Moderate Alkalai 0 1 2 0

Not Alkalai 0 0 5c 0Low Alkalai 0 0 0 0

Not Alkalai 0 12 0 0None Alkalai 0 1a 0 0

Not Alkalai 12 1 0 0

Maize Processing, 11aaCrow (Plains): use alkali, but have noCrow (Plains): use alkali, but have no

cultivation of corn, and littlecultivation of corn, and littleconsumption of maizeconsumption of maize

Their use of maize historically comesTheir use of maize historically comesfrom the Hidatsafrom the Hidatsa

Crow split from Hidatsa to becomeCrow split from Hidatsa to becomenomadic buffalo hunters, butnomadic buffalo hunters, butmaintained the food habit of alkalimaintained the food habit of alkaliprocessing corn (with wood ashes)processing corn (with wood ashes)

Maize Processing, 12bbPaez (Andean): Most Andeans don't process,Paez (Andean): Most Andeans don't process,

but the Paez dobut the Paez do

Archaeological evidence suggests that theArchaeological evidence suggests that theColombian area where the Paez live didColombian area where the Paez live didnot develop corn cultivation like others innot develop corn cultivation like others inthe Peruvian Andesthe Peruvian Andes

The Maize complex, complete with alkaliThe Maize complex, complete with alkaliprocessing was introduced into Colombianprocessing was introduced into ColombianAndes late (like in Southwest U.S.),Andes late (like in Southwest U.S.),influencing the Paez and othersinfluencing the Paez and others

Maize Processing, 13ccPapago (Southwest U.S.): don't use alkali, butPapago (Southwest U.S.): don't use alkali, but

are moderate producers and consumers ofare moderate producers and consumers ofcorncorn

Limits of the arid environment prohibitsLimits of the arid environment prohibitsyearyear--round cultivation and high reliance onround cultivation and high reliance oncorncorn

Papago don't store maize nor allow it toPapago don't store maize nor allow it tofully ripenfully ripen----they eat it in the roasting earthey eat it in the roasting earstage, gorging at a time when other food isstage, gorging at a time when other food isabundant (Thrifty Genotype)abundant (Thrifty Genotype)

Chili Peppers

6

Chili Peppers

Most widely used food seasoning in the worldMost widely used food seasoning in the world

Fiery taste comes from capsaicinFiery taste comes from capsaicin

Capsaicin is not detected by mostCapsaicin is not detected by mostvertebratesvertebrates

Especially birds who are excellent seedEspecially birds who are excellent seeddispersersdispersers

Mammals are sensitive to the burningMammals are sensitive to the burning

•• Most mammals damage the seeds inMost mammals damage the seeds inthe process of consumptionthe process of consumption

Humans are sensitive, so whyHumans are sensitive, so whyconsume?consume?

Peppers

Peppers are early domesticates (~ 9000 ya inPeppers are early domesticates (~ 9000 ya inMesoAmerica)MesoAmerica)

Moved from New World to Old WorldMoved from New World to Old World

Rapidly adopted in European cuisinesRapidly adopted in European cuisines

Nutritional Benefits of Chili PeppersNutritional Benefits of Chili Peppers

One of the top plant sources of vitamin AOne of the top plant sources of vitamin A

Rich source of vitamin C and the BRich source of vitamin C and the Bvitaminsvitamins

Other reasons for use

Lower body temperatureLower body temperature

Capsaicin causes sweating whichCapsaicin causes sweating whichfacilitates evaporative coolingfacilitates evaporative cooling

Facilitates digestion of starches,Facilitates digestion of starches,increases gastric secretion, stimulatesincreases gastric secretion, stimulatesappetiteappetite

Helps to liven up bland staplesHelps to liven up bland staples

Inhibit bacterial growthInhibit bacterial growth

Based on 4578 meat-based recipes from 93traditional cookbooks from 36 countries

Based on 4578 meat-based recipes from 93traditional cookbooks from 36 countries

23%

Microbial Inhibition Temperature and chili use

Pro

po

rtio

no

fM

ea

t-ba

se

dR

ec

ipes

r = 0.757, p < 0.001;Strongest relationship

of all spices

7

Chili peppers

Acquisition of chili pepper preferencedepends on social influences

Convert an aversion to a preferenceConvert an aversion to a preference

Chili peppers cause oral pain, salivation,Chili peppers cause oral pain, salivation,runny nose, eyes waterrunny nose, eyes water

In rural Mexican villages, 2In rural Mexican villages, 2--6 year olds are6 year olds areexposed to peppers, permitted to refuseexposed to peppers, permitted to refuse

Children observe elders enjoying pepperChildren observe elders enjoying pepper

By 5By 5--8 years, most had acquired taste8 years, most had acquired tastefor "hot" foodsfor "hot" foods

Chili peppers

The pepper flavor and salivating enhance anThe pepper flavor and salivating enhance anotherwise dry and bland mealotherwise dry and bland meal

Deeper reasons include "thrillDeeper reasons include "thrill--seeking"seeking"behaviorbehavior----pain without any real dangerpain without any real danger

Mouth burn stimulates endorphin excretionMouth burn stimulates endorphin excretion(morphine(morphine--like neurotransmitters)like neurotransmitters)

Some evidence that pepper eaters areSome evidence that pepper eaters areless reactive to other endorphinless reactive to other endorphin--generating pain relieversgenerating pain relievers

Tasting

Much individualMuch individualvariation in tastingvariation in tasting

Supertasters, mediumSupertasters, mediumtasters, nontasterstasters, nontasters

Supertasters verySupertasters verysensitive to bitter,sensitive to bitter,sweet, spicysweet, spicy

Avoid peppers,Avoid peppers,cruciferouscruciferousvegetables, fattyvegetables, fattyfoodsfoods

Nontasters lessNontasters lesssensitive to spicysensitive to spicy

1

The Fava Bean TabooThe Fava Bean Taboo

Based on a presentation by Christine NewkirkBased on a presentation by Christine Newkirk

Interpretations of Fava BeanInterpretations of Fava BeanTabooTaboo

19001900 –– 1960: Taboos linked to magico1960: Taboos linked to magico--religious belief systemsreligious belief systems

19601960’’ss –– 19901990’’s: Taboos linked to favism,s: Taboos linked to favism,anan illness resulting from genetically basedillness resulting from genetically basedenzyme deficiencyenzyme deficiency

19901990’’s forward: Previous modelss forward: Previous modelscontested, new synthesis exploredcontested, new synthesis explored

The Fava Bean: BackgroundThe Fava Bean: Background

The fava bean has been calledThe fava bean has been called ““the beanthe bean”” ofofantiquityantiquity

The genus name,The genus name, FabaFaba, refers to its round shape, refers to its round shape

The bean was widely considered to possessThe bean was widely considered to possessspiritual and magical propertiesspiritual and magical properties Often the target of specified tabooOften the target of specified taboo

Pythagoras is credited with issuing a ban on favaPythagoras is credited with issuing a ban on favaconsumption due to the beanconsumption due to the bean’’s fleshs flesh--likelikecharactercharacter His community near Croton eschewed the beansHis community near Croton eschewed the beans

Early Interpretation of FavaEarly Interpretation of FavaBean TabooBean Taboo

Andrews (1949) viewed taboo from aAndrews (1949) viewed taboo from acultural evolutionary and symboliccultural evolutionary and symbolicperspectiveperspective

Explained that the fleshExplained that the flesh--like characterlike character

attributed to the bean was reason for anattributed to the bean was reason for aninstitutionalized taboo in some parts of theinstitutionalized taboo in some parts of theancient worldancient world

Like a ban on meat eatingLike a ban on meat eating

Revision of the MeaningRevision of the Meaning--CenteredCenteredApproachApproach

New data from genetic and biologicalNew data from genetic and biologicalresearch suggested a biological basis forresearch suggested a biological basis forthe fava bean taboos: G6PD deficiencythe fava bean taboos: G6PD deficiencywas linked to favism through laboratorywas linked to favism through laboratorytests.tests.

Biocultural Evolutionary ModelBiocultural Evolutionary Model

Katz and Schall (1979) sought to understandKatz and Schall (1979) sought to understandresponses to fava beans and favism in light ofresponses to fava beans and favism in light ofselection pressures and human adaptabilityselection pressures and human adaptability

Katz correlated fava bean consumptionKatz correlated fava bean consumptionrestrictions with prevalence of G6PD deficienciesrestrictions with prevalence of G6PD deficienciesthroughout the worldthroughout the world

The new biocultural evolutionary approach:The new biocultural evolutionary approach:

Food PracticesFood Practices ↔↔ Genetic CharacteristicsGenetic Characteristics

2

G6PD HemolysisG6PD Hemolysis

Red blood cells will hemolyze or burst when theRed blood cells will hemolyze or burst when theoxidant stress level becomes too highoxidant stress level becomes too high Hemolysis occurs in G6PD deficient individuals due toHemolysis occurs in G6PD deficient individuals due to

the consumption of certain foods or drugsthe consumption of certain foods or drugs Substances that increase the oxidation of glutathione,Substances that increase the oxidation of glutathione,

thereby diminishing the available GSH for oxidation ofthereby diminishing the available GSH for oxidation ofperoxide, creating a potential for hemolysisperoxide, creating a potential for hemolysis Fava Beans contains vicine and convicine whose metabolitesFava Beans contains vicine and convicine whose metabolites

can cause a hemolytic crisis in Gdcan cause a hemolytic crisis in GdMedMed individualsindividuals

Many antiMany anti--malarial drugs, sulfonamides, sulfones and othermalarial drugs, sulfonamides, sulfones and otherdrugs produce the same reaction in severely deficientdrugs produce the same reaction in severely deficientindividualsindividuals

Can also cause the oxidation of hemoglobin, making itCan also cause the oxidation of hemoglobin, making itlose the ability to be a reversible oxygen carrierlose the ability to be a reversible oxygen carrier

FavismFavism

The Fava Bean (Vicia faba) is a favored cultigenThe Fava Bean (Vicia faba) is a favored cultigenin areas where the GdMed allele is commonin areas where the GdMed allele is commonincluding Greeceincluding Greece

Vicine and convicine make up about 0.5% of the wetVicine and convicine make up about 0.5% of the wetweight of the Fava beanweight of the Fava bean

These compounds metabolize to divicine and isouramil in theThese compounds metabolize to divicine and isouramil in theintestineintestine

These metabolites decrease RBC reduced glutathione (GSH)These metabolites decrease RBC reduced glutathione (GSH)

Increase the production of hydrogen peroxide and freeIncrease the production of hydrogen peroxide and freeradicalsradicals

Creates a severe oxidant stress in G6PD deficient cellsCreates a severe oxidant stress in G6PD deficient cells

Glu

cose

-6-P

ho

sph

ate

Deh

yd

rog

ena

se

G6PD and Fava BeansG6PD and Fava Beans

2 H202

(HydrogenPeroxide)

2 H20+ 02

GSH(Reduced

Glutathione)

GSSG(Oxidized

Glutathione)

NADP+

(NicotinamideAdenine Di-Phosphate)

NADPH(Reduced

NicotinamideAdenine Di-Phosphate)

G-6-P(Glucose-6-Phosphate)

Glucose

ADPATP

Glu

tath

ion

eP

ero

xid

ase

6-P-G(6-Phospho-gluconate)

F-6-P(Fructose-6-Phosphate)

Phosphoglucoisomerase

Pyruvic Acid+ 2 ATP + 2H+

70% Embden-Meyerhof Pathway

Glyceraldehyde-3-P+ CO2 + H+ +

NADPH

30

%P

ento

seP

ho

sph

ate

Sh

un

t

Glucokinase

Glu

tath

ion

eR

edu

ctase

Fava Beans: Vicine and Convicine

Malaria in the RBCMalaria in the RBC

Plasmodium protozoans preferentially attackPlasmodium protozoans preferentially attackimmature RBC but P. falciparum can invade RBCimmature RBC but P. falciparum can invade RBCof all agesof all ages

Plasmodium oxidizes RBC NADPH from the PentosePlasmodium oxidizes RBC NADPH from the PentosePhosphate pathway for its metabolismPhosphate pathway for its metabolism

This results in a deficiency of RBC GSH, most severe in G6PDThis results in a deficiency of RBC GSH, most severe in G6PDdeficient individuals, leading to peroxidedeficient individuals, leading to peroxide--induced hemolysisinduced hemolysiswhich curtails the development of Plasmodiumwhich curtails the development of Plasmodium

After several cell cycles the Plasmodium can adapt to produceAfter several cell cycles the Plasmodium can adapt to produceits own G6PD, reducing the adaptive benefit of G6PD deficiencyits own G6PD, reducing the adaptive benefit of G6PD deficiency

Glu

cose

-6-P

hosp

ha

teD

ehy

dro

gen

ase

G6PD and MalariaG6PD and Malaria

2 H202

(HydrogenPeroxide)

2 H20+ 02

GSH(Reduced

Glutathione)

GSSG(Oxidized

Glutathione)

NADP+

(NicotinamideAdenine Di-Phosphate)

NADPH(Reduced

NicotinamideAdenine Di-Phosphate)

G-6-P(Glucose-6-Phosphate)

Glucose

ADPATP

Glu

tath

ion

eP

ero

xid

ase

6-P-G(6 Phospho-gluconate)

F-6-P(Fructose-6-Phosphate)

Phosphoglucoisomerase

Pyruvic Acid+ 2 ATP + 2H+

70% Embden-Meyerhof Pathway

Glyceraldehyde-3-P+ CO2 + H+ +

NADPH

30

%P

ento

seP

ho

sph

ate

Sh

un

t

Glucokinase

Glu

tath

ion

eR

edu

ctase

Plasmodium

Fava Beans and MalariaFava Beans and Malaria

Recall that fava beans contain compounds thatRecall that fava beans contain compounds thatmetabolize to powerful oxidantsmetabolize to powerful oxidants

In a cell that is oxidantIn a cell that is oxidant--stressed by Plasmodiumstressed by Plasmodiuminfection, the addition of another strong oxidant caninfection, the addition of another strong oxidant canlead to a rapid buildlead to a rapid build--up of peroxideup of peroxide

In vitro and in vivo (mouse) studies indicate a mildIn vitro and in vivo (mouse) studies indicate a mildsuppressant effect of divicine and isouramil onsuppressant effect of divicine and isouramil onPlasmodium in G6PD normalsPlasmodium in G6PD normals This effect is even greater in G6PD deficient individualsThis effect is even greater in G6PD deficient individuals

3

Glu

cose

-6-P

ho

sph

ate

Deh

yd

rog

ena

se

G6PD, Fava Beans, and MalariaG6PD, Fava Beans, and Malaria

2 H202

(HydrogenPeroxide)

2 H20+ 02

GSH(Reduced

Glutathione)

GSSG(Oxidized

Glutathione)

NADP+

(NicotinamideAdenine Di-Phosphate)

NADPH(Reduced

NicotinamideAdenine Di-Phosphate)

G-6-P(Glucose-6-Phosphate)

Glucose

ADPATP

Glu

tath

ion

eP

ero

xid

ase

6-P-G(6-Phospho-gluconate)

F-6-P(Fructose-6-Phosphate)

Phosphoglucoisomerase

Pyruvic Acid+ 2 ATP + 2H+

70% Embden-Meyerhof Pathway

Glyceraldehyde-3-P+ CO2 + H+ +

NADPH

30

%P

ento

seP

ho

sph

ate

Sh

un

t

GlucokinaseG

luta

thio

ne

Red

uct

ase

Fava Beans: Vicine and Convicine

Plasmodium

Distribution of G6PD, Fava Beans, and MalariaDistribution of G6PD, Fava Beans, and Malaria

All features are found together inarea of Ancient Greece and Rome

The Pythagorean Bean BanThe Pythagorean Bean Ban

Simoons conducted a comprehensiveSimoons conducted a comprehensivereview in 1998review in 1998

Concluded that the fava bean ban had noConcluded that the fava bean ban had norelationship to G6PD deficiency in therelationship to G6PD deficiency in thepopulation of Crotonpopulation of Croton

Argued for a strictly magicoArgued for a strictly magico--religiousreligious

explanation for the fava tabooexplanation for the fava taboo

SimoonsSimoons

A study of Greeks from Samos (the origin of PythagorasA study of Greeks from Samos (the origin of Pythagoras’’

parents) found no G6PD deficiency at allparents) found no G6PD deficiency at all

Studies of populations in Italy and Greece find rates ofStudies of populations in Italy and Greece find rates of

G6PD deficiency ranging from zero to 35 percent,G6PD deficiency ranging from zero to 35 percent,

including mild to severe forms of the deficiencyincluding mild to severe forms of the deficiency

Based on descent lines and geography, Simoons positsBased on descent lines and geography, Simoons posits

that the rate of G6PD deficiency among Greek males inthat the rate of G6PD deficiency among Greek males in

the Ancient Greek colonies in Southern Italy at the timethe Ancient Greek colonies in Southern Italy at the time

of Pythagoras averaged 2of Pythagoras averaged 2--4 percent4 percent

He asserts that only around 13 percent of these individualsHe asserts that only around 13 percent of these individuals

would have developed favismwould have developed favism

SimoonsSimoons’’ ConclusionsConclusions

G6PD deficiency was not frequent in anyG6PD deficiency was not frequent in anypopulations during Pythagoraspopulations during Pythagoras’’ timetime There is no account of favism in the medical records,There is no account of favism in the medical records,

despite common knowledge of malaria and itsdespite common knowledge of malaria and itssymptomssymptoms

Restrictions against fava bean consumption wereRestrictions against fava bean consumption weremost likely linked solely to cultural meaning:most likely linked solely to cultural meaning:

The richness of ancient views surrounding the beanThe richness of ancient views surrounding the bean——ininterms of death and the underworld, decay, spirits of theterms of death and the underworld, decay, spirits of thedead, flatulence, meat eating and cannibalism, sex anddead, flatulence, meat eating and cannibalism, sex andregeneration, and purity and impurityregeneration, and purity and impurity——makes Pythagoreanmakes Pythagoreanrevulsion at the thought of eating beans all the morerevulsion at the thought of eating beans all the moreunderstandable. . . . [T]he powerful magicounderstandable. . . . [T]he powerful magico--religiousreligiousmotives reported in both Greece and Rome were quitemotives reported in both Greece and Rome were quitesufficient to have brought on the bans of fava beans all bysufficient to have brought on the bans of fava beans all bythemselves, without implicating favism at all.themselves, without implicating favism at all.

So where does that leave us?So where does that leave us?

The continued cultivation of fava beans inThe continued cultivation of fava beans inareas where there are substantialareas where there are substantialnumbers of individuals with G6PDnumbers of individuals with G6PDdeficiency may be related to malariadeficiency may be related to malaria

The ancient taboo on fava beanThe ancient taboo on fava beanconsumption probably has nothing to doconsumption probably has nothing to dowith G6PD deficiencywith G6PD deficiency

4

ReferencesReferences

Katz, SH. and Schall, J. 1979. Fava beanKatz, SH. and Schall, J. 1979. Fava beanconsumption and biocultural evolution.consumption and biocultural evolution.Medical Anthropology. 3: 459Medical Anthropology. 3: 459--476.476.

Simoons, F. 1998. Plants of Life, Plants ofSimoons, F. 1998. Plants of Life, Plants ofDeath. Madison, WI:University ofDeath. Madison, WI:University ofWisconsin Press.Wisconsin Press.

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1

Adaptation to Dairy Products

History of Dairy Production

Origins in the Old World

Early pictorial evidence from theSahara Desert during the Neolithic (c.5500-2000 B.C.)

Domesticated faunal assemblagesfrom Neolithic sites

Recent ‘Direct’ Detecting ofDairying

Extraction of lipids (fats) from Neolithicvessels

Can distinguish isotopic 13C of dairyfat vs. adipose fats (milk vs. meat)

Demonstrated processing of dairyproducts ~4500 B.C. in Britain

As early as ~6th Millenium B.C. in SEEurope

Milking Populations

Northern and Central Europe

South Asia (India), Tibet and Mongolia

Pastoralist populations in Africa (Masaiand the Fulani)

Some circumpolar peoples in Siberia(reindeer milk)

Non-milking Peoples

New World populations

Old World: Eastern Asia (China,Japan) and most other groups of Eastand SE Asia

Despite presence of pastoralists (e.g.,Masai) in Africa, 1/3 of continent isnon-milking

Why Not Adopt Dairying?

Ecological Reasons:

– Africa: tropical zone with tsetse-borne sleepingsickness that decimates cattle herds

– Shortage of grazing land; need to devote to cropsand to plough animals

Cultural:

– Distaste for drinking milk (seems like urine)

Biological:

– Lactose intolerance

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Human Biological Adaptationto Dairy Foods

Lactose - main sugar in milk– Also called milk sugar

– Only significant CHO from animal origin

Lactase (intestinal enzyme) – required todigest lactose– Breaks bond between galactose and glucose

Most humans, like other mammals, loselactase after infancy

Persistence of intestinal lactase in somepopulations

What is Lactose Intolerance?

Primary adult lactose malabsorption

Symptoms: bloating, flatulence, diarrhea,cramps, sometimes nausea and vomiting

Determined by the administration in a fastingstate of a 50 g dose of lactose in water:– measure subsequent rise in blood glucose level

(no rise = lactose intolerant)

– appearance of additional hydrogen in breath

– (increase = lactose intolerant)

– direct intestinal biopsy

Lactose Digestion

Genetic trait inherited as an autosomal-dominant characteristic

– Malabsorption caused by DD or Dd genotype

Most common among peoples of Northernand Central Europe & other populations thateat dairy products

Genetic mutation that must have arisen withthe rise of dairy production

Population Distribution ofLactose Intolerance

Approximately:– 79% of Native American people;

– 75% of African-Americans;

– 51% of Hispanics;

– 21% of Europeans

In Africa, Asia and Latin America prevalencerates range from 15 -100% depending onpopulation studied– Populations formed by recent admixture between

lactose-absorbing and non-absorbing ethnicgroup exhibit mixed numbers (as expected).

• Ex: African Americans – about 80%

Distribution of intolerance Explanations

Cultural-Historical hypothesis– Lactase persistence is an adaptation to milk

consumption and pastoralism

High latitude, low UV areas at risk forcalcium deficiency– Lactose promotes calcium absorption

• Could explain high persistence in Northern Europe

In arid settings lactose digestion will aidhydration– High frequency of persistence among desert

dwelling pastoralists

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Cultural-Historical Hypothesis

Simoons (1974) postulated that certaingroups produced dairy products in highamounts– Processed foods like yogurt and cheese contain

less lactose; began with these and moved on tounprocessed milk

Certain individuals had ability to digestlactose without distress

Through process of natural selection thisgenetic mutation increased in the population

Simoons (1974) continued…

Have to consider all factors when tryingto explain why some populationsadopted milking and others didn’t

i.e. Ecology of land and animals;cultural interest in cattle, goats, anddairying; and physiological adaptationto milk digestion

High Latitude Hypothesis

Consumption of fresh milk– High latitude, low UV, low vitamin D synthesis

puts people at risk of rickets– Digested milk products like cheese and yogurt

have reduced lactose content– Only fresh milk has full lactose value– Lactose aids in the absorption of calcium

Northern Europe has higher rates of lactasepersistence than Southern Europe– Southern Europeans consume more milk as

cheese and yogurt– Northern Europeans at higher risk of Vitamin D

and calcium deficiency

Arid Area Hypothesis

Fresh milk consumption increaseswater intake, especially important inhot-dry environments

Desert Pastoralists tend to have highlactase persistence rates– Those without lactase would be subject to

diarrhea which would acceleratedehydration

– Bedouin, Tuareg, Fulani cases wouldsupport this model

Phylogenetic Analysis

A phylogenetic analysis comparingmilking rates to lactose digestioncapacity (LDC) supports the cultural-historical explanation

High latitude and Arid Setting modelsare not supported

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Milking High LDC

Milking came first

Hidden Sources of Lactose

Bread and other baked goods

Processed breakfast cereals

Instant potatoes, soups, and breakfast drinks

Margarine

Lunch meats

Salad dressings

Candies and other snacks

Institute of Medicine CalciumGuidelines (1997)

1,200 mg51-70 years

1,000 mg19-50 years

1,300 mg9-18 years

800 mg4-8 years

500 mg1-3 years

270 mg6-12 months

210 mg0-6 months

Amount of Daily CalciumAge Group

Nutritional Implications ofLactose Intolerance

May be forcing dairy products onpeople who cannot digest them

Are there alternatives?

– Butter, aged cheese

– Low-lactose dairy products

– Foods rich in calcium

Lactaid

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Alternative Foods with Calcium

225 mgTofu (3 oz.)

274 mgMolasses (2 tbsp)

226 mgSardines (3 oz.)

156 mgChinese cabbage (bok choy) 1 cup

94-177 mgBroccoli (1 cup)

Inappropriate Substitutes

Swiss chard, rhubarb and spinach areall rich in calcium, but contain oxalatesthat stop calcium absorption in thebody

Calcium is absorbed and used onlywhen there is enough vitamin D in thebody (eggs, liver, and sunlight)

– Or in the presence of lactose

Summary

Biological adaptation to dairy productsprobably genetic, enabling certain people todigest lactose better than others

Adaptation probably occurred in milkingpopulations

Milking occurred as a result of a combinationof ecological, cultural, and biological factors

Dietary recommendations should includedairy alternatives for lactose intolerantpeople